Coke is a solid carbon fuel and carbon source used to melt and reduce iron ore in the production of steel. In one process, known as the “Thompson Coking Process,” coke is produced by batch feeding pulverized coal to an oven that is sealed and heated to very high temperatures for 24 to 48 hours under closely-controlled atmospheric conditions. Coking ovens have been used for many years to convert coal into metallurgical coke. During the coking process, finely crushed coal is heated under controlled temperature conditions to devolatilize the coal and form a fused mass of coke having a predetermined porosity and strength. Because the production of coke is a batch process, multiple coke ovens are operated simultaneously.
Coal particles or a blend of coal particles are charged into hot ovens, and the coal is heated in the ovens in order to remove volatile matter (“VM”) from the resulting coke. The coking process is highly dependent on the oven design, the type of coal, and conversion temperature used. Typically, ovens are adjusted during the coking process so that each charge of coal is coked out in approximately the same amount of time. Once the coal is fully coked out, the resulting coke may take the form of a substantially intact coke loaf that is then quenched with water or another liquid. Because the coke loaf may stay intact during quenching, the quenching liquid may encounter difficulty penetrating the intact coke loaf. Moreover, an unacceptable amount of coke may be lost during the quenching process. For example, coke may fly out of the container in which it is otherwise contained (i.e., “flied coke”) during the quenching process. In addition, an amount of particulate matter may be generated during the quenching process and vented through the quench tower into the atmosphere outside of the quench tower.
These problems of conventional systems lead to myriad disadvantages that lower the overall efficiency of the coking operation. For example, the difficulty of penetrating an intact or partially intact coke loaf may result in increased water usage, longer quench times that can cripple the throughput of the coke plant, excessive moisture levels in the coke, large variations in coke moisture, and increased risk of melting plant equipment if the coke is not cooled rapidly enough. In addition, conventional systems may vent an unacceptable level of particulate matter into the environment, thereby creating a need for more effective environmental controls. These problems may occur in any coking operation but are particularly applicable to stamp charged coking operations, in which the coal is compacted prior to heating. As another example, a large amount of flied coke or particulate matter that escapes the quench tower may lower the efficiency of the coking operation by yielding less coke for screening and loading into rail cars or trucks for shipment at the end of the quenching process. Therefore, a need exists for an improved quench tower that provides a quenching operation that more efficiently penetrates an amount of coke with a quenching liquid, reduces the amount of coke loss due to flied coke, reduces the amount of particulate matter that escapes the quench tower, and reduces the particulate matter, emissions, and steam that escapes the bottom of the quench tower.